Encyclopedia Astronautica
Delta 7425-9.5


American orbital launch vehicle. Four stage vehicle consisting of 4 x GEM-40 + 1 x EELT Thor/RS-27A + 1 x Delta K + 1 x Star 48B with 2.9 m (9.5 foot) diameter fairing)

Status: Active.
Gross mass: 170,000 kg (370,000 lb).
Height: 39.00 m (127.00 ft).
Diameter: 2.44 m (8.00 ft).
Thrust: 3,020.00 kN (678,920 lbf).
Apogee: 400,000 km (240,000 mi).
First Launch: 1998.12.11.
Last Launch: 2002.07.03.
Number: 3 .

More... - Chronology...


Associated Countries
Associated Spacecraft
  • MCO American Mars orbiter. One launch, 1998.12.11, Mars Climate Orbiter. The Mars Climate Orbiter was to have accomplished mapping and weather studies of Mars and served as a relay for data from the Mars Polar Lander. More...
  • Mars Polar Lander American Mars lander. One launch, 1999.01.03. The Mars Polar Lander had the mission of studying Martian volatiles (frozen water and carbon dioxide) and climate history. The Martian polar regions were the best places to conduct these studies. More...

See also
  • Delta The Delta launch vehicle was America's longest-lived, most reliable, and lowest-cost space launch vehicle. Development began in 1955 and it continued in service in the 21st Century despite numerous candidate replacements. More...

Associated Manufacturers and Agencies
  • Douglas American manufacturer of rockets, spacecraft, and rocket engines. Boeing Huntington Beach, Huntington Beach, CA, USA. More...

Associated Programs
  • Discovery The Discovery program was begun by NASA in the early 1990s as the planetary counterpart to the Explorer program. More...
  • Mars Surveyor A series of lower-cost missions devoted to the mapping of Mars from Mars orbit. Designed to accomplish at less cost the mission assigned to the failed Mars Observer. More...

Associated Launch Sites
  • Cape Canaveral America's largest launch center, used for all manned launches. Today only six of the 40 launch complexes built here remain in use. Located at or near Cape Canaveral are the Kennedy Space Center on Merritt Island, used by NASA for Saturn V and Space Shuttle launches; Patrick AFB on Cape Canaveral itself, operated the US Department of Defense and handling most other launches; the commercial Spaceport Florida; the air-launched launch vehicle and missile Drop Zone off Mayport, Florida, located at 29.00 N 79.00 W, and an offshore submarine-launched ballistic missile launch area. All of these take advantage of the extensive down-range tracking facilities that once extended from the Cape, through the Caribbean, South Atlantic, and to South Africa and the Indian Ocean. More...
  • Cape Canaveral LC17B Delta launch complex. Part of a dual launch pad complex built for the Thor ballistic missile program in 1956. Upgraded over the decades for use with Thor, Delta, Delta II, and Delta III launch vehicles, it remained in use for over half a century. More...
  • Cape Canaveral LC17A Delta launch complex. Part of a dual launch pad complex built for the Thor ballistic missile program in 1956. Pad 17A supported Thor, Delta, and Delta II launches into the 21st Century. More...

Associated Stages
  • Delta K N2O4/Aerozine-50 propellant rocket stage. Loaded/empty mass 6,954/950 kg. Thrust 43.63 kN. Vacuum specific impulse 319 seconds. More...
  • Delta Thor XLT-C Lox/Kerosene propellant rocket stage. Loaded/empty mass 101,900/5,900 kg. Thrust 1,054.20 kN. Vacuum specific impulse 302 seconds. More...
  • GEM 40 Solid propellant rocket stage. Loaded/empty mass 13,064/1,361 kg. Thrust 492.93 kN. Vacuum specific impulse 274 seconds. More...
  • PAM-D Solid propellant rocket stage. Loaded/empty mass 2,141/232 kg. Thrust 67.16 kN. Vacuum specific impulse 292 seconds. More...

Delta 7425-9.5 Chronology


1998 December 11 - . 18:45 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC17A. Launch Pad: SLC17A. LV Family: Delta. Launch Vehicle: Delta 7425-9.5. LV Configuration: Delta 7425-9.5 D264.
  • Mars Climate Orbiter - . Mass: 629 kg (1,386 lb). Nation: USA. Agency: JPL. Manufacturer: Martin. Program: Mars Surveyor. Class: Mars. Type: Mars probe. Spacecraft: MCO. Decay Date: 1999-09-23 . USAF Sat Cat: 25571 . COSPAR: 1998-073A. The Mars Climate Orbiter was the second flight of the Mars Surveyor Program. The probe was to enter a 160 km x 38600 km polar orbit around Mars on September 23,1999, and use aerobraking to reach a 373 km x 437 km x 92.9 degree sun-synchronous mapping orbit by November 23 1999. While the Mars Orbit Insertion burn began as planned on September 23, 1999 at 08:50 GMT, no signal was received after the spacecraft went behind the planet. Subsequent investigation showed that the spacecraft had plunged deep into the Martian atmosphere, with its closest approach to Mars being 57 km. It was concluded that the spacecraft burnt up in the atmosphere. It was later found that cutbacks in tracking, combined with incorrect values in a look-up table imbedded deep in the spacecraft software (use of pounds force instead of newtons) were to blame. This failure led to a shake-up of NASA's 'faster, better, cheaper' approach to unmanned spaceflight. Additional Details: here....

1999 January 3 - . 20:21 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC17B. Launch Pad: SLC17B. LV Family: Delta. Launch Vehicle: Delta 7425-9.5. LV Configuration: Delta 7425-9.5 D265.
  • Mars Polar Lander - . Mass: 576 kg (1,269 lb). Nation: USA. Agency: JPL. Manufacturer: Martin. Class: Mars. Type: Mars probe. Spacecraft: Mars Polar Lander. Decay Date: 1999-12-03 . USAF Sat Cat: 25605 . COSPAR: 1999-001A. The Mars Polar Lander was placed by the first burn of the second stage into a 157 x 245 km x 28.35 deg parking orbit. The second stage restarted at 20:55 GMT and shut down in a 226 x 740 km x 25.8 deg Earth orbit. The solid rocket third stage (a Star 48B with a Nutation Control System and a yo-yo despin device) then ignited and put the spacecraft into solar orbit, separating at 21:02 GMT. Mars Polar Lander was to land near the south pole of Mars on December 3, 1999, and conduct conduct a three month mission, trenching near its landing site and testing for the presense of frozen water and carbon dioxide. Attached were two Deep Space 2 Microprobes, penetrators which would impact the Martian surface separately from the lander and return data on subsurface conditions from widely spaced points.

    When the spacecraft reached Mars on December 3, the lander separated from the cruise stage at 19:51 UTC and the two penetrators, Scott and Amundsen, were to separate about 20 seconds later. No further communications were ever received from the spacecraft. Landing had been expected at 20:01 UTC at 76.1S 195.3W, with the penetrators landing a few kilometres from each other at 75.0S 196.5W.

    This failure resulted in a review and reassessment of NASA's 'faster, better, cheaper' approach to planetary missions.

  • DS2 Microprobe 2 - . Nation: USA. Agency: Douglas. Class: Mars. Type: Mars probe. Decay Date: 1999-03-23 . USAF Sat Cat: 25607 . COSPAR: 1999-001C. Apogee: 645 km (400 mi). Perigee: 220 km (130 mi). Inclination: 25.8000 deg. Period: 93.23 min.
  • DS2 Microprobe 1 - . Nation: USA. Agency: Douglas. Class: Mars. Type: Mars probe. USAF Sat Cat: 25606 . COSPAR: 1999-001B.

2002 July 3 - . 06:47 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC17A. Launch Pad: SLC17A. LV Family: Delta. Launch Vehicle: Delta 7425-9.5. LV Configuration: Delta 7425-9.5 D292 / Star 30.
  • Contour - . Payload: Discovery 6. Mass: 1,005 kg (2,215 lb). Nation: USA. Agency: NASA; Cornell. Manufacturer: APL. Program: Discovery. Class: Comet. Type: Comet probe. Spacecraft: Contour. USAF Sat Cat: 27457 . COSPAR: 2002-034A. Apogee: 108,614 km (67,489 mi). Perigee: 212 km (131 mi). Inclination: 30.6000 deg. Period: 2,486.10 min. Launch delayed from July 1st. The latest NASA Discovery mission was successfully launched on Jul 3. The CONTOUR (Comet Nucleus Tour) probe, built and operated by the Johns Hopkins University's Applied Physics Laboratory (APL), began its five year mission to explore three comets, using repeated encounters with the earth to modify its orbit in order to reach each target. The first burn of the second stage completed at 0659 UTC putting the spacecraft in a 185 x 197 km x 29.7 deg parking orbit. At 0746 UTC the second stage restarted for a short 4s burn to 185 x 309 km x 29.7 deg, and then separated once the PAM-D (ATK Star 48B) solid third stage was spun up. The 1.5 minute burn of the third stage motor at 0748 UTC put it and CONTOUR in a 90 x 106689 km x 30.5 deg phasing orbit. By July 8 CONTOUR's orbit was 214 x 106686 km x 29.8 deg. CONTOUR stayed in this phasing orbit until August 15, when it was injected into solar orbit using its internal ATK Star 30 solid motor. Flyby of the first target, comet 2P/Encke, was scheduled for Nov 2003.

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